• Ultracold atoms in a "Rydberg-dress"

    Ultracold atoms in a Rydberg dress picture1 | Fig. 1: From the starting state densely filled with atoms (left), a ring-like structure emerges due to the long range interaction (right). Graphic: MPQ, Quantum Many-Body Systems Division

    Scientists at the MPQ (Garching) and MPIPKS (Dresden) have developed a novel technique to let atoms interact over large distances.

    Many properties of our everyday world can be explained if atoms are thought of as small, solid marbles, which feel each other only if brought in direct contact with each other. The temperature of the air surrounding us, for example, is the result of uncountable, continuously occurring collisions between its constituents. Contrary to this, we also know effects which arise from the interplay between two distant objects. Well-known examples are two magnets which can affect each other also at quite a distance, or the formation of a salt crystal as a regular arrangement of positively charged sodium and negatively charged chlorine ions, which are bound together at large distances by electrical attraction.